Modern vehicles include a vast array of sensors, such as air bag sensors, tire pressure sensors, engine sensors, seat belt sensors, and many others. The air bag sensors, for example, provide data about the vehicle's operation (e.g., wheel speed, deceleration, etc.) to an airbag control unit (ACU). Based on the data received from the air bag sensors, the ACU can determine when air bags within a vehicle should be deployed.
As the number of vehicular sensors increases, integration is becoming a serious challenge for automakers. For example, wires connecting an ACU to its corresponding air bag sensors can be several meters long. These wires are a significant cost factor in automotive systems and contribute to the overall weight of the vehicle. Because of this, some conventional wiring interfaces, such as PSI5 and DSI for example, limit the number of wires to two lines. Unfortunately, absent countermeasures, the inductances and capacitances of these wires can give rise to noise at a resonant frequency set by the inductances and capacitances of the wires.
In some conventional implementations, an RLC filter (which includes a resistor and an optional by-pass inductor in parallel with the resistor) may be arranged between an ECU and its corresponding sensors. This RLC filter can be designed to attenuate noise at the resonant frequency, thereby helping to improve the performance of the vehicular sensing system.